Add blob resolver to snippet GraphQL type

In order to retrieve single or multiple blobs
from snippets and avoid retrieving all at the
same time, we add a resolver to the blobs field in the
snippet type.

We can now pass a string or an array of files to retrieve.

app/assets/javascripts/snippets/components/edit.vue

@@ -151,7 +151,7 @@ export default {
       this.newSnippet = false;
     },
     onSnippetFetch(snippetRes) {
-      if (snippetRes.data.snippets.edges.length === 0) {
+      if (snippetRes.data.snippets.nodes.length === 0) {
         this.onNewSnippetFetched();
       } else {
         this.onExistingSnippetFetched();

app/assets/javascripts/snippets/components/snippet_blob_view.vue

@@ -23,6 +23,7 @@ export default {
         return {
           ids: this.snippet.id,
           rich: this.activeViewerType === RICH_BLOB_VIEWER,
+          paths: [this.blob.path],
         };
       },
       update(data) {
@@ -79,8 +80,10 @@ export default {
     },
     onContentUpdate(data) {
       const { path: blobPath } = this.blob;
-      const { blobs } = data.snippets.edges[0].node;
-      const updatedBlobData = blobs.find(blob => blob.path === blobPath);
+      const {
+        blobs: { nodes: dataBlobs },
+      } = data.snippets.nodes[0];
+      const updatedBlobData = dataBlobs.find(blob => blob.path === blobPath);
       return updatedBlobData.richData || updatedBlobData.plainData;
     },
   },

app/assets/javascripts/snippets/components/snippet_header.vue

@@ -18,6 +18,7 @@ import DeleteSnippetMutation from '../mutations/deleteSnippet.mutation.graphql';
 import CanCreatePersonalSnippet from '../queries/userPermissions.query.graphql';
 import CanCreateProjectSnippet from '../queries/projectPermissions.query.graphql';
 import { joinPaths } from '~/lib/utils/url_utility';
+import { fetchPolicies } from '~/lib/graphql';
 
 export default {
   components: {
@@ -37,6 +38,7 @@ export default {
   },
   apollo: {
     canCreateSnippet: {
+      fetchPolicy: fetchPolicies.NO_CACHE,
       query() {
         return this.snippet.project ? CanCreateProjectSnippet : CanCreatePersonalSnippet;
       },

app/assets/javascripts/snippets/fragments/snippetBase.fragment.graphql

@@ -12,6 +12,7 @@ fragment SnippetBase on Snippet {
   httpUrlToRepo
   sshUrlToRepo
   blobs {
+    nodes {
       binary
       name
       path
@@ -26,6 +27,7 @@ fragment SnippetBase on Snippet {
         ...BlobViewer
       }
     }
+  }
   userPermissions {
     adminSnippet
     updateSnippet

app/assets/javascripts/snippets/index.js

@@ -16,7 +16,7 @@ function appFactory(el, Component) {
   }
 
   const apolloProvider = new VueApollo({
-    defaultClient: createDefaultClient(),
+    defaultClient: createDefaultClient({}, { batchMax: 1 }),
   });
 
   const {

app/assets/javascripts/snippets/mixins/snippets.js

@@ -11,9 +11,16 @@ export const getSnippetMixin = {
           ids: this.snippetGid,
         };
       },
-      update: data => data.snippets.edges[0]?.node,
+      update: data => {
+        const res = data.snippets.nodes[0];
+        if (res) {
+          res.blobs = res.blobs.nodes;
+        }
+
+        return res;
+      },
       result(res) {
-        this.blobs = res.data.snippets.edges[0]?.node?.blobs || blobsDefault;
+        this.blobs = res.data.snippets.nodes[0]?.blobs || blobsDefault;
         if (this.onSnippetFetch) {
           this.onSnippetFetch(res);
         }

app/assets/javascripts/snippets/queries/snippet.blob.content.query.graphql

-query SnippetBlobContent($ids: [ID!], $rich: Boolean!) {
+query SnippetBlobContent($ids: [ID!], $rich: Boolean!, $paths: [String!]) {
   snippets(ids: $ids) {
-    edges {
-      node {
+    nodes {
       id
-        blobs {
+      blobs(paths: $paths) {
+        nodes {
           path
           richData @include(if: $rich)
           plainData @skip(if: $rich)

app/assets/javascripts/snippets/queries/snippet.query.graphql

@@ -4,8 +4,7 @@
 
 query GetSnippetQuery($ids: [ID!]) {
   snippets(ids: $ids) {
-    edges {
-      node {
+    nodes {
       ...SnippetBase
       ...SnippetProject
       author {
@@ -13,5 +12,4 @@ query GetSnippetQuery($ids: [ID!]) {
       }
     }
   }
-  }
 }

app/graphql/resolvers/snippets/blobs_resolver.rb

+# frozen_string_literal: true
+
+module Resolvers
+  module Snippets
+    class BlobsResolver < BaseResolver
+      include Gitlab::Graphql::Authorize::AuthorizeResource
+
+      alias_method :snippet, :object
+
+      argument :paths, [GraphQL::STRING_TYPE],
+               required: false,
+               description: 'Paths of the blobs'
+
+      def resolve(**args)
+        authorize!(snippet)
+
+        return [snippet.blob] if snippet.empty_repo?
+
+        paths = Array(args.fetch(:paths, []))
+
+        if paths.empty?
+          snippet.blobs
+        else
+          snippet.repository.blobs_at(transformed_blob_paths(paths))
+        end
+      end
+
+      def authorized_resource?(snippet)
+        Ability.allowed?(context[:current_user], :read_snippet, snippet)
+      end
+
+      private
+
+      def transformed_blob_paths(paths)
+        ref = snippet.default_branch
+        paths.map { |path| [ref, path] }
+      end
+    end
+  end
+end

app/graphql/types/snippet_type.rb

@@ -69,10 +69,11 @@ module Types
           null: false,
           deprecated: { reason: 'Use `blobs`', milestone: '13.3' }
 
-    field :blobs, type: [Types::Snippets::BlobType],
+    field :blobs, type: Types::Snippets::BlobType.connection_type,
           description: 'Snippet blobs',
           calls_gitaly: true,
-          null: false
+          null: true,
+          resolver: Resolvers::Snippets::BlobsResolver
 
     field :ssh_url_to_repo, type: GraphQL::STRING_TYPE,
           description: 'SSH URL to the snippet repository',

app/presenters/snippet_presenter.rb

@@ -32,15 +32,9 @@ class SnippetPresenter < Gitlab::View::Presenter::Delegated
   end
 
   def blob
-    blobs.first
-  end
+    return snippet.blob if snippet.empty_repo?
 
-  def blobs
-    if snippet.empty_repo?
-      [snippet.blob]
-    else
-      snippet.blobs
-    end
+    blobs.first
   end
 
   private

doc/api/graphql/reference/gitlab_schema.graphql

@@ -16250,7 +16250,32 @@ type Snippet implements Noteable {
   """
   Snippet blobs
   """
-  blobs: [SnippetBlob!]!
+  blobs(
+    """
+    Returns the elements in the list that come after the specified cursor.
+    """
+    after: String
+
+    """
+    Returns the elements in the list that come before the specified cursor.
+    """
+    before: String
+
+    """
+    Returns the first _n_ elements from the list.
+    """
+    first: Int
+
+    """
+    Returns the last _n_ elements from the list.
+    """
+    last: Int
+
+    """
+    Paths of the blobs
+    """
+    paths: [String!]
+  ): SnippetBlobConnection
 
   """
   Timestamp this snippet was created
@@ -16473,6 +16498,41 @@ input SnippetBlobActionInputType {
   previousPath: String
 }
 
+"""
+The connection type for SnippetBlob.
+"""
+type SnippetBlobConnection {
+  """
+  A list of edges.
+  """
+  edges: [SnippetBlobEdge]
+
+  """
+  A list of nodes.
+  """
+  nodes: [SnippetBlob]
+
+  """
+  Information to aid in pagination.
+  """
+  pageInfo: PageInfo!
+}
+
+"""
+An edge in a connection.
+"""
+type SnippetBlobEdge {
+  """
+  A cursor for use in pagination.
+  """
+  cursor: String!
+
+  """
+  The item at the end of the edge.
+  """
+  node: SnippetBlob
+}
+
 """
 Represents how the blob content should be displayed
 """

doc/api/graphql/reference/gitlab_schema.json

@@ -47549,24 +47549,69 @@
               "name": "blobs",
               "description": "Snippet blobs",
               "args": [
-
-              ],
+                {
+                  "name": "paths",
+                  "description": "Paths of the blobs",
                   "type": {
-                "kind": "NON_NULL",
-                "name": null,
-                "ofType": {
                     "kind": "LIST",
                     "name": null,
                     "ofType": {
                       "kind": "NON_NULL",
                       "name": null,
                       "ofType": {
-                      "kind": "OBJECT",
-                      "name": "SnippetBlob",
+                        "kind": "SCALAR",
+                        "name": "String",
                         "ofType": null
                       }
                     }
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "after",
+                  "description": "Returns the elements in the list that come after the specified cursor.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "before",
+                  "description": "Returns the elements in the list that come before the specified cursor.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "String",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "first",
+                  "description": "Returns the first _n_ elements from the list.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Int",
+                    "ofType": null
+                  },
+                  "defaultValue": null
+                },
+                {
+                  "name": "last",
+                  "description": "Returns the last _n_ elements from the list.",
+                  "type": {
+                    "kind": "SCALAR",
+                    "name": "Int",
+                    "ofType": null
+                  },
+                  "defaultValue": null
                 }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "SnippetBlobConnection",
+                "ofType": null
               },
               "isDeprecated": false,
               "deprecationReason": null
@@ -48220,6 +48265,118 @@
           "enumValues": null,
           "possibleTypes": null
         },
+        {
+          "kind": "OBJECT",
+          "name": "SnippetBlobConnection",
+          "description": "The connection type for SnippetBlob.",
+          "fields": [
+            {
+              "name": "edges",
+              "description": "A list of edges.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "SnippetBlobEdge",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "nodes",
+              "description": "A list of nodes.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "LIST",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "SnippetBlob",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "pageInfo",
+              "description": "Information to aid in pagination.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "OBJECT",
+                  "name": "PageInfo",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "SnippetBlobEdge",
+          "description": "An edge in a connection.",
+          "fields": [
+            {
+              "name": "cursor",
+              "description": "A cursor for use in pagination.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "node",
+              "description": "The item at the end of the edge.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "SnippetBlob",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "SnippetBlobViewer",

doc/api/graphql/reference/index.md

@@ -2303,7 +2303,6 @@ Represents a snippet entry.
 | ----- | ---- | ----------- |
 | `author` | User | The owner of the snippet |
 | `blob` **{warning-solid}** | SnippetBlob! | **Deprecated:** Use `blobs`. Deprecated in 13.3 |
-| `blobs` | SnippetBlob! => Array | Snippet blobs |
 | `createdAt` | Time! | Timestamp this snippet was created |
 | `description` | String | Description of the snippet |
 | `descriptionHtml` | String | The GitLab Flavored Markdown rendering of `description` |

spec/frontend/snippets/components/edit_spec.js

@@ -148,17 +148,17 @@ describe('Snippet Edit app', () => {
 
   // Ideally we wouldn't call this method directly, but we don't have a way to trigger
   // apollo responses yet.
-  const loadSnippet = (...edges) => {
-    if (edges.length) {
+  const loadSnippet = (...nodes) => {
+    if (nodes.length) {
       wrapper.setData({
-        snippet: edges[0],
+        snippet: nodes[0],
       });
     }
 
     wrapper.vm.onSnippetFetch({
       data: {
         snippets: {
-          edges,
+          nodes,
         },
       },
     });

spec/frontend/snippets/components/snippet_blob_view_spec.js

@@ -140,10 +140,10 @@ describe('Blob Embeddable', () => {
         async ({ snippetBlobs, currentBlob, expectedContent }) => {
           const apolloData = {
             snippets: {
-              edges: [
+              nodes: [
                 {
-                  node: {
-                    blobs: snippetBlobs,
+                  blobs: {
+                    nodes: snippetBlobs,
                   },
                 },
               ],

spec/graphql/resolvers/snippets/blobs_resolver_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Resolvers::Snippets::BlobsResolver do
+  include GraphqlHelpers
+
+  describe '#resolve' do
+    let_it_be(:current_user) { create(:user) }
+    let_it_be(:snippet) { create(:personal_snippet, :private, :repository, author: current_user) }
+
+    context 'when user is not authorized' do
+      let(:other_user) { create(:user) }
+
+      it 'raises an error' do
+        expect do
+          resolve_blobs(snippet, user: other_user)
+        end.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+      end
+    end
+
+    context 'when using no filter' do
+      it 'returns all snippet blobs' do
+        expect(resolve_blobs(snippet).map(&:path)).to contain_exactly(*snippet.list_files)
+      end
+    end
+
+    context 'when using filters' do
+      context 'when paths is a single string' do
+        it 'returns an array of files' do
+          path = 'CHANGELOG'
+
+          expect(resolve_blobs(snippet, args: { paths: path }).first.path).to eq(path)
+        end
+      end
+
+      context 'when paths is an array of string' do
+        it 'returns an array of files' do
+          paths = ['CHANGELOG', 'README.md']
+
+          expect(resolve_blobs(snippet, args: { paths: paths }).map(&:path)).to contain_exactly(*paths)
+        end
+      end
+    end
+  end
+
+  def resolve_blobs(snippet, user: current_user, args: {})
+    resolve(described_class, args: args, ctx: { current_user: user }, obj: snippet)
+  end
+end

spec/graphql/types/snippet_type_spec.rb

@@ -16,6 +16,15 @@ RSpec.describe GitlabSchema.types['Snippet'] do
     expect(described_class).to have_graphql_fields(*expected_fields)
   end
 
+  describe 'blobs field' do
+    subject { described_class.fields['blobs'] }
+
+    it 'returns blobs' do
+      is_expected.to have_graphql_type(Types::Snippets::BlobType.connection_type)
+      is_expected.to have_graphql_resolver(Resolvers::Snippets::BlobsResolver)
+    end
+  end
+
   context 'when restricted visibility level is set to public' do
     let_it_be(:snippet) { create(:personal_snippet, :repository, :public, author: user) }
 
@@ -142,9 +151,30 @@ RSpec.describe GitlabSchema.types['Snippet'] do
 
   describe '#blobs' do
     let_it_be(:snippet) { create(:personal_snippet, :public, author: user) }
-    let(:query_blobs) { subject.dig('data', 'snippets', 'edges')[0]['node']['blobs'] }
+    let(:query_blobs) { subject.dig('data', 'snippets', 'edges')[0].dig('node', 'blobs', 'edges') }
+    let(:paths) { [] }
+    let(:query) do
+      %(
+        {
+          snippets {
+            edges {
+              node {
+                blobs(paths: #{paths}) {
+                  edges {
+                    node {
+                      name
+                      path
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      )
+    end
 
-    subject { GitlabSchema.execute(snippet_query_for(field: 'blobs'), context: { current_user: user }).as_json }
+    subject { GitlabSchema.execute(query, context: { current_user: user }).as_json }
 
     shared_examples 'an array' do
       it 'returns an array of snippet blobs' do
@@ -158,8 +188,8 @@ RSpec.describe GitlabSchema.types['Snippet'] do
       it_behaves_like 'an array'
 
       it 'contains the first blob from the snippet' do
-        expect(query_blobs.first['name']).to eq blob.name
-        expect(query_blobs.first['path']).to eq blob.path
+        expect(query_blobs.first['node']['name']).to eq blob.name
+        expect(query_blobs.first['node']['path']).to eq blob.path
       end
     end
 
@@ -170,10 +200,22 @@ RSpec.describe GitlabSchema.types['Snippet'] do
       it_behaves_like 'an array'
 
       it 'contains all the blobs from the repository' do
-        resulting_blobs_names = query_blobs.map { |b| b['name'] }
+        resulting_blobs_names = query_blobs.map { |b| b['node']['name'] }
 
         expect(resulting_blobs_names).to match_array(blobs.map(&:name))
       end
+
+      context 'when specific path is set' do
+        let(:paths) { ['CHANGELOG'] }
+
+        it_behaves_like 'an array'
+
+        it 'returns specific files' do
+          resulting_blobs_names = query_blobs.map { |b| b['node']['name'] }
+
+          expect(resulting_blobs_names).to match(paths)
+        end
+      end
     end
   end
 

spec/presenters/snippet_presenter_spec.rb

@@ -163,25 +163,4 @@ RSpec.describe SnippetPresenter do
       end
     end
   end
-
-  describe '#blobs' do
-    let(:snippet) { personal_snippet }
-
-    subject { presenter.blobs }
-
-    context 'when snippet does not have a repository' do
-      it 'returns an array with one SnippetBlob' do
-        expect(subject.size).to eq(1)
-        expect(subject.first).to eq(snippet.blob)
-      end
-    end
-
-    context 'when snippet has a repository' do
-      let(:snippet) { create(:snippet, :repository, author: user) }
-
-      it 'returns an array with all repository blobs' do
-        expect(subject).to match_array(snippet.blobs)
-      end
-    end
-  end
 end

spec/requests/api/graphql/mutations/snippets/create_spec.rb

@@ -79,18 +79,20 @@ RSpec.describe 'Creating a Snippet' do
     end
 
     shared_examples 'creates snippet' do
-      it 'returns the created Snippet' do
+      it 'returns the created Snippet', :aggregate_failures do
         expect do
           subject
         end.to change { Snippet.count }.by(1)
 
+        snippet = Snippet.last
+        created_file_1 = snippet.repository.blob_at('HEAD', file_1[:filePath])
+        created_file_2 = snippet.repository.blob_at('HEAD', file_2[:filePath])
+
+        expect(created_file_1.data).to match(file_1[:content])
+        expect(created_file_2.data).to match(file_2[:content])
         expect(mutation_response['snippet']['title']).to eq(title)
         expect(mutation_response['snippet']['description']).to eq(description)
         expect(mutation_response['snippet']['visibilityLevel']).to eq(visibility_level)
-        expect(mutation_response['snippet']['blobs'][0]['plainData']).to match(file_1[:content])
-        expect(mutation_response['snippet']['blobs'][0]['fileName']).to match(file_1[:file_path])
-        expect(mutation_response['snippet']['blobs'][1]['plainData']).to match(file_2[:content])
-        expect(mutation_response['snippet']['blobs'][1]['fileName']).to match(file_2[:file_path])
       end
 
       context 'when action is invalid' do

spec/requests/api/graphql/mutations/snippets/update_spec.rb

@@ -73,7 +73,6 @@ RSpec.describe 'Updating a Snippet' do
         aggregate_failures do
           expect(blob_to_update.data).to eq updated_content
           expect(blob_to_delete).to be_nil
-          expect(blob_in_mutation_response(updated_file)['plainData']).to match(updated_content)
           expect(mutation_response['snippet']['title']).to eq(updated_title)
           expect(mutation_response['snippet']['description']).to eq(updated_description)
           expect(mutation_response['snippet']['visibilityLevel']).to eq('public')
@@ -100,7 +99,6 @@ RSpec.describe 'Updating a Snippet' do
           aggregate_failures do
             expect(blob_at(updated_file).data).to eq blob_to_update.data
             expect(blob_at(deleted_file).data).to eq blob_to_delete.data
-            expect(blob_in_mutation_response(deleted_file)['plainData']).not_to be_nil
             expect(mutation_response['snippet']['title']).to eq(original_title)
             expect(mutation_response['snippet']['description']).to eq(original_description)
             expect(mutation_response['snippet']['visibilityLevel']).to eq('private')
@@ -108,10 +106,6 @@ RSpec.describe 'Updating a Snippet' do
         end
       end
 
-      def blob_in_mutation_response(filename)
-        mutation_response['snippet']['blobs'].select { |blob| blob['name'] == filename }[0]
-      end
-
       def blob_at(filename)
         snippet.repository.blob_at('HEAD', filename)
       end